Parasite-specific IgA response in infected children by Giardia intestinalis from rural communities of Venezuela.

Abstract

Giardiasis is an infection caused by Giardia intestinalis into the small intestine that affects children in school age. The aim of the work was evaluated the specific IgA anti-Giardia antibodies in serum of children from rural communities were evaluated 100 children of 3 to 13 years old and measurement the levels of IgA antibody response against immunodominant antigens of Giardia intestinalis by ELISA and Westernblot. The soluble extract of Giardia intestinalis and fractions were obtained by differential centrifugation. Electrophoretic pattern showed several proteins from 205 to 14kDa, and sera of infected children recognized proteins of 205, 176, a region from 76 to 41kDa, and a band of 23kDa in the fraction 2. The IgA antibody response anti-Giardia for to soluble extract was higher in infected children compared to uninfected children (0.29 ± 0.16 vs. 0.07 ± 0.04; p ≤ 0.05). The IgA antibody response against the fraction 2 was higher in infected group than controls (1.0 ± 0.2 vs. 0.75 ± 0.26; p ≥ 0.05), the fraction 3 showed similar response to the soluble extract (0.45 ± 0.12 vs. 0.3 ± 0.12; p ≥ 0.05). The infection by Giardia intestinalis produce specific IgA antibodies directed to the proteins of the fraction 2. These proteins could be tested as antigens for serological diagnosis of giardiasis.